CeO2 Nanoparticle-Loaded MnO2 Nanoflowers for Selective Catalytic Reduction of NOx with NH3 at Low Temperatures

Shun Li; Zuquan Zheng; Zhicheng Zhao; Youling Wang; Yao Yao; Yong Liu; Jianming Zhang; Zuotai Zhang

doi:10.3390/molecules27154863

CeO₂ Nanoparticle-Loaded MnO₂ Nanoflowers for Selective Catalytic Reduction of NO_x with NH₃ at Low Temperatures

Molecules. 2022 Jul 29;27(15):4863. doi: 10.3390/molecules27154863.

Authors

Shun Li¹, Zuquan Zheng², Zhicheng Zhao³, Youling Wang⁴, Yao Yao³, Yong Liu³, Jianming Zhang¹, Zuotai Zhang²

Affiliations

¹ Institute of Quantum and Sustainable Technology (IQST), School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China.
² Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
³ Foshan (Southern China) Institute for New Materials, Foshan 528200, China.
⁴ Shunde Graduate School, University of Science and Technology Beijing, Foshan 528399, China.

Abstract

CeO₂ nanoparticle-loaded MnO₂ nanoflowers, prepared by a hydrothermal method followed by an adsorption-calcination technique, were utilized for selective catalytic reduction (SCR) of NO_x with NH₃ at low temperatures. The effects of Ce/Mn ratio and thermal calcination temperature on the NH₃-SCR activity of the CeO₂-MnO₂ nanocomposites were studied comprehensively. The as-prepared CeO₂-MnO₂ catalysts show high NO_x reduction efficiency in the temperature range of 150-300 °C, with a complete NO_x conversion at 200 °C for the optimal sample. The excellent NH₃-SCR performance could be ascribed to high surface area, intimate contact, and strong synergistic interaction between CeO₂ nanoparticles and MnO₂ nanoflowers of the well-designed composite catalyst. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) characterizations evidence that the SCR reaction on the surface of the CeO₂-MnO₂ nanocomposites mainly follows the Langmuir-Hinshelwood (L-H) mechanism. Our work provides useful guidance for the development of composite oxide-based low temperature NH₃-SCR catalysts.

Keywords: Mn-Ce mixed oxide; NOx conversion; ion-adsorption; selective catalytic reduction.

Abstract

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